摘要
利用Gleeble-1500D热模拟机对新型超高强度热冲压用钢22MnB5Nb进行等温单向拉伸实验,研究了其在变形温度为650~950℃,应变速率为0.1,1.0,10s^(-1)下的热变形行为,并采用3种本构分析方法,即基于传统拟合回归方法的Arrhenius型、考虑材料常数应变补偿的Arrhenius型和本工作新提出的基于Quasi-Newton BFGS算法的Arrhenius型本构方程来描述22MnB5Nb钢的热变形行为。结果表明:22MnB5Nb钢表现出典型的加工硬化和动态回复软化行为,变形温度与应变速率均对其流变应力有较大影响;3种方程均可以准确预测实验钢的峰值流变应力,其中,Quasi-Newton BFGS算法具有可一次性求解所有材料参数、求解步骤简单和预测精度最高(R=0.99578,Re=11.03MPa,E=2.48%)的特点,考虑材料常数应变补偿的Arrhenius型本构方程预测精度相对较低,但能直接预测不同变形条件下的流变应力曲线且可以较好地预测变形过程中的加工硬化效应、动态回复软化效应和应变速率强化效应。
The hot deformation behavior of the advanced ult 22MnB5Nb was studied through the isothermal uniaxial tensile 0.1, 1.0s-1 and 10s-1 by Gleeble 1500D system. The conven equation, the Arrhenius-type model considering the material con Arrhenius-type model based on Quasi-Newton BFGS algorithm temperature deformation behavior of 22MnB5Nb. The results ra-high strength hot stamping steel tests at 650-950℃ and strain rates of tional Arrhenius-type hyperbolic sine stant strain compensation and the new were established to describe the high- indicate that 22MnB5Nb steel showstypical work hardening and dynamic recovery softening behavior during hot tensile. And the strain rate and deformation temperature have significant effects on the flow stress. The peak flow stress val- ues predicted by these models are highly consistent with the experimental values, and the Quasi-New- ton BFGS algorithm can solve all the material parameters in one time and it is simpler in calculationprocess and has the highest accurate（R=0. 99578, Re=11. 03MPa, E=2.48%）, while, the Arrhe- nius-type model considering material constant strain compensation with lower accuracy, but can di- rectly predicts not only the flow stress curve under different deformation conditions, but also the work hardening behavior, the dynamic recovery behavior and the strain rate strengthening effect of the ex- perimental steel during the deformation process.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2016年第5期15-21,共7页
Journal of Materials Engineering
基金
长江青年基金资助项目(2015cqn51)
长江大学油气钻完井工具研究中心创新基金资助项目(DCT201503)
关键词
热冲压用钢
热变形行为
本构模型
NB
hot stamping steel
hot deformation behavior
constitutive model
Nb
